US4702988A - Process for producing toner for developing electrostatic images - Google Patents

Process for producing toner for developing electrostatic images Download PDF

Info

Publication number
US4702988A
US4702988A US07/018,535 US1853587A US4702988A US 4702988 A US4702988 A US 4702988A US 1853587 A US1853587 A US 1853587A US 4702988 A US4702988 A US 4702988A
Authority
US
United States
Prior art keywords
process according
monomer composition
monomer
particles
dispersion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US07/018,535
Other languages
English (en)
Inventor
Hiroshi Fukumoto
Toshikazu Ohnishi
Kohzoh Arahara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Assigned to CANON KABUSHIKI KAISHA, 3-30-2 SHIMOMARUKO, OHTA-KU, TOKYO, JAPAN A CORP. OF JAPAN reassignment CANON KABUSHIKI KAISHA, 3-30-2 SHIMOMARUKO, OHTA-KU, TOKYO, JAPAN A CORP. OF JAPAN ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ARAHARA, KOHZOH, FUKUMOTO, HIROSHI, OHNISHI, TOSHIKAZU
Application granted granted Critical
Publication of US4702988A publication Critical patent/US4702988A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/087—Binders for toner particles
    • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/0802—Preparation methods
    • G03G9/0804—Preparation methods whereby the components are brought together in a liquid dispersing medium
    • G03G9/0806—Preparation methods whereby the components are brought together in a liquid dispersing medium whereby chemical synthesis of at least one of the toner components takes place

Definitions

  • the present invention relates to a process for producing a toner for developing electrostatic or electrostatically charged images in image forming process such as electrophotography, electrostatography and electrostatic printing, and more particularly to a process for producing a toner for developing electrostatic images through suspension polymerization including a step of granulation or droplet formation for effectively forming particles (droplets) with a sharp particle size distribution.
  • the methods of developing electrostatic images formed on recording media used heretofore in electrophotography, electrostatic recording and electrostatic printing may roughly include the liquid developing method using a developer comprising an insulating liquid and a various pigment or dye dispersed therein; and the dry developing method such as the cascade method, the fur brush method, the magnetic brush method, the impression method, and the powder cloud method respectively using fine particles called "toner” comprising a colorant such as carbon black dispersed in natural or synthetic polymers or waxes.
  • the above mentioned liquid developing method involves problems that the treatment of the developer is troublesome and undesirable odor occurs during development and fixation, and even thereafter. For this reason, the above mentioned dry developing method is frequently used.
  • the toner for developing electrostatic images is generally produced by mixing a binder such as a vinyl polymer such as polystyrene or polyacrylic acid ester, epoxy polymer, petroleum polymer or ester condensate; and a colorant such as dye, carbon black or magnetic material; and subjecting the mixture to melt kneading, cooling, pulverization and classification into an average particle size of 1-50 ⁇ . It is required for the toner thus formed to satisfy various properties such as storage stability, durability, moisture resistance, electrostatic characteristic, fluidity, fixability, and image characteristic.
  • a binder such as a vinyl polymer such as polystyrene or polyacrylic acid ester, epoxy polymer, petroleum polymer or ester condensate
  • a colorant such as dye, carbon black or magnetic material
  • the production of a toner through suspension polymerization has been proposed.
  • the production of a dry toner through suspension polymerization proposed heretofore involves the following problems.
  • In the production of a toner by an ordinary suspension polymerization process it is very difficult to effectively control a particle size to a desired size in a granulation or particle (or more precisely droplet) formation step wherein a liquid monomer composition comprising a polymerizable monomer and a colorant.
  • the resultant particles have a broad particle size distribution and contain very large size particles, so that the proportion of particles within a proper size range is low and the productivity is poor.
  • a dispersion stabilizer is used in order to form particles of a monomer composition and stabilize the particles.
  • a hardly water-soluble or substantially water-insoluble inorganic fine powder such as that of BaSO 4 , CaSO 4 , CaCO 3 and silica acid (silica); and a water-soluble polymer such as polyvinyl alcohol or gelatine or a water-soluble surfactant, may generally be used singly or in combination.
  • a dispersion stabilizer has a strong affinity to water for its function.
  • a dispersion stabilizer remains in a toner, the toner is caused to have a lowered development ability and a lowered transfer efficiency mainly because of decrease in chargeability.
  • a deterioration of image quality due to decrease in copied image density, decrease in resolution, blurring and scattering.
  • an object of the present invention is to provide a toner production process capable of efficiently producing a toner with an extremely narrow particle size distribution while easily controlling the average particle size, in production of a toner for developing electrostatic images through the suspension polymerization process.
  • Another object of the invention is to provide a process for effectively producing a dry toner with a small particle size.
  • Another object is to provide a process for producing a toner with a uniform and sharp particle size distribution by using a small amount of fine powdery dispersion stabilizer in toner production through suspension polymerization.
  • Another object is to provide a process for producing a toner which has good powder characteristic and also has good developing, transferring, fixing and cleaning characteristics.
  • Still another object is to provide a process for producing a toner at a low cost and a good productivity.
  • a process for producing a toner for developing electrostatic latent images comprising:
  • FIG. 1 is a sectional view illustrating a homogenizer which can be used in the granulation step according to the present invention
  • FIGS. 2 to 4 are flow charts each showing steps involved in an embodiment of the process according to the present invention.
  • FIG. 5 is a schematic view illustrating a developing apparatus used for evaluating the electrophotographic characteristics of polymerization toners obtained in Examples of the present invention and Comparative Examples.
  • a piston-type high-pressure homogenizer manufactured by Gaulin Corp. may be raised.
  • the high pressure homogenizer comprises a pressurizing mechanism for pressuring a process liquid, a valve mechanism for ejecting or jetting the pressurized process liquid, and an impacting mechanism for causing impringement of the ejected process liquid.
  • the apparatus is applicable for forming particles or droplets with sizes on the order of microns in the presence of a solid powdery dispersant.
  • a monomer composition comprising a polymerizable monomer such as styrene, a colorant such as carbon black and a polymerization initiator is preliminarily dispersed for pregranulation in a liquid dispersion medium in the presence of a solid fine powdery dispersion stabilizer such as silica fine powder by a dispersion means such as a high shearing-force stirring-type mixer.
  • a dispersion means such as a high shearing-force stirring-type mixer.
  • a liquid dispersion 1 containing the predispersed monomer composition is pressurized up to a prescribed pressure of 10 kg/cm 2 or above and is supplied to a high pressure section 2.
  • a volumetric plunger pump is used as a pressurizing means as it is excellent in metering characteristic and capable of arbitrarily adjusting the pressure.
  • the pressurized dispersion 1 is jetted through a gap 5 between a valve sheet 3 and a valve 4 constituting a valve mechanism against an impact ring 6, which is an impacting, impinging a striking member, because of a pressure difference between the high pressure section 2 and a low pressure section 7 and is caused to impinge on the impact ring 6.
  • the coarse particles of the monomer composition are converted into fine particles.
  • agglomerates, of a fine powdery dispersion stabilizer which do not effectively function are further disintegrated to approach individual fine particles, so that the dispersion stabilization ability is increased as a whole.
  • the fine particles of the monomer composition are protected by the fine powdery dispersion stabilizer with an enhanced stabilization function.
  • the dispersed particles are further subjected to one or more times of additional pressurization and granulation when a sharp particle size is not obtained through a single granulation step, the possibility of further communication is much smaller than in the conventional granulation method.
  • toner particles continuously through a preliminary dispersion step, a pressurization step, a granulation step and a polymerization step, as shown in FIG. 2. It is preferred, in order to obtain a sharp particle size distribution, that after the completion of the first cycle of the pressurization and granulation steps, the dispersion is continuously or intermittently recycled to repeat the pressurization and granulation steps as shown in FIG. 3. It is also possible to repeat the pressurization and granulation steps n times in series wherein n is generally 1 to 9.
  • the preliminary dispersion of a monomer composition into a liquid dispersion medium is effected by using a high shearing force mixer such as TK-homomixer.
  • the preliminary dispersion may be conducted for 1 to 60 minutes.
  • the monomer composition can contain a polymerization initiator already in this stage.
  • a polymerization initiator can be added into a liquid medium containing monomer composition particles adjusted to a polymerization temperature, thereby to effect suspension polymerization.
  • the liquid dispersion prepared in the preliminary dispersion step is pressurized to 10 kg/m 2 or above so as to be ejected into a low pressure section through a gap or nozzle to be dispersed into fine particles. Below 10 kg/cm 2 , the pressure difference between the high pressure and low pressure sections is small, so that the ejection speed of the dispersion becomes insufficient and an effective granulation or dispersion effect cannot be attained.
  • the dispersion is pressurized to 100-700 kg/cm 2 , particularly about 300-650 kg/cm 2 so as to provide a pressure difference between the high pressure and low pressure sections of about 100 kg/cm 2 or above, particularly about 300-650 kg/cm 2 .
  • the monomer composition in the dispersion jetted or ejected at a high speed may well be dispersed into a particle size of about 1-10 ⁇ under the adjusting action of the fine powdery dispersion stabilizer.
  • the dispersion may be recycled to the pressuring step to be granulated again.
  • the number of recycling (the number of passes) may preferably be 2-10.
  • coarse particles are converted into fine particles, and particles with a prescribed size are protected by the fine powdery dispersion stabilizer with an enhanced dispersion stabilization ability, so that a possibility of further reduction in size is very low and the resultant particle size distribution becomes very sharp.
  • the liquid temperature in the granulation step may be adjusted to such a temperature as to provide a viscosity of 1-1,000,000 cps, preferably 10-100,000 cps, of the monomer composition, so that the resultant monomer composition particles have a particle size of 1-10 ⁇ which provides a weight average particle size of 1-10 ⁇ of a toner for developing.
  • the liquid dispersion medium water or an aqueous medium consisting predominantly of water is used, so that the temperature of the liquid dispersion may preferably be set to 20°-80° C., particularly 40°-70° C.
  • the liquid dispersion medium may preferably be present in an amount of 100-5000 wt. parts, preferably 200-1000 wt. parts per 100 wt. parts of the monomer composition; and the fine powdery dispersion stabilizer may be used in an amount of 0.1-15 wt. %, preferably 1-10 wt. %, further preferably 3-8 wt. %, based on the liquid dispersion medium.
  • monomer composition particles with a uniform size of about 1-10 ⁇ in terms of a weight-average particle size can be formed by using a fine powdery dispersion stabilizer in an amount on the order of about 1/2-1/10 according to the present invention. It is also possible to effect the granulation in a shorter period than before.
  • the polymerizable monomer applicable to the present invention may be those having a reactive double bond such as CH 2 ⁇ C ⁇ .
  • examples thereof include: styrene and its derivatives such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dode
  • a low-softening point compound having a releasing characteristic including waxes such as paraffin wax; and low-molecular weight polyolefins such as low-molecular weight polyethylene and low-molecular weight polypropylene in order to improve the fixability and anti-offset characteristic in the hot-roller fixation.
  • the amount of addition thereof may be 1-300 wt. parts per 100 wt. parts of the polymerizable monomer.
  • low softening point compound examples include paraffins, waxes, low-molecular weight polyolefins, modified waxes having aromatic group, natural waxes, long-chain carboxylic acids having a long hydrocarbon chain (CH 3 --CH 2 ) 11 or --CH 2 -- 12 or longer aliphatic chains) including 12 or more carbon atoms, and esters thereof.
  • Different low-softening point compounds can be mixed.
  • Examples of commercially available products include Paraffin Wax (Nihon Sekiyu K.K.), Paraffin Wax (Nihon Seiro K.K.), Microwax (Nihon Sekiyu K.K.), Microcrystalline Wax (Nihon Seiro K.K.), Hard Paraffin Wax (Nihon Seiro K.K.), PE-130 (Hoechst), Mitsui Hi-Wax 110P (Mitsui Sekiyu Kagaku K.K.), Mitsui Hi-Wax 220P (ditto), Mitsui Hi-Wax 660P (ditto), Mitsui Hi-Wax 320P (ditto), Mitsui Hi-Wax 410P (ditto), Mitsui Hi-Wax 420P (ditto), Hiletz T-100X (ditto), Hiletz T-200X (ditto), Hiletz T-300X (ditto), Petrosin 80 (dit
  • polymerizable monomer composition it is also possible to incorporate a crosslinking agent as exemplified below in order to produce a crosslinked polymer.
  • a crosslinking agent as exemplified below
  • crosslinking agent may appropriately include: divinylbenzene, divinylnaphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis(4-methacryloxydiethoxyphenyl)propane, 2,2'-bis(4-acryloxydiethoxyphenyl)propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dibromone
  • the amount of use of the crosslinking agent may suitably be 0.001-15 wt. %, preferably 0.1-10 wt. %, of the polymerizable monomer.
  • the monomer composition contains a colorant.
  • the colorant may comprise known dyes or pigments such as carbon black or grafted carbon black obtained by coating the surface of carbon black with a resin.
  • the colorant may be contained in a proportion of 0.1-30 wt. % based on the amount of the polymerizable monomer.
  • a charge controller or a fluidity improver as desired into the toner (internal addition).
  • Such a charge controller or a fluidity improver can also be mixed with the toner particles (external addition).
  • the charge controller may for example be a metal complex of an organic compound having a carboxyl group or a nitrogen-containing group, a metal-containing dye, or a nigrosine.
  • the fluidity improver or a cleaning aid for the surface of a latent image-bearing member may for example be colloidal silica or an aliphatic acid metal salt. It is also possible to incorporate a filler such as calcium carbonate or fine powdery silica in an amount of 0.5-20 wt. % in the toner for the purpose of extension. Further, it is possible to add a fluidity improver such as polytetrafluoroethylene fine powder or zinc stearate powder in order to disintegrate the agglomerate of the toner particles and improve the fluidity.
  • a filler such as calcium carbonate or fine powdery silica in an amount of 0.5-20 wt. % in the toner for the purpose of extension.
  • a fluidity improver such as polytetrafluoroethylene fine powder or zinc stearate powder in order to disintegrate the agglomerate of the toner particles and improve the fluidity.
  • the magnetic particles usable in the present invention may be a substance magnetizable when placed in a magnetic field, such as powder of a ferromagnetic metal such as iron, cobalt and nickel, or an alloy or compound thereof such as magnetite, hematite and ferrite.
  • the magnetic particles may have a particle size of 0.05-5 ⁇ , preferably 0.1-1 ⁇ . In order to produce a small particle size toner, it is preferred to use magnetic particles of 0.8 ⁇ or smaller.
  • the content of the magnetic particles may suitably be 5-70 wt. %, preferably 10-60 wt.
  • the magnetic particles have been treated with a treating agent such as silane coupling agent or titanate coupling agent or with an appropriate reactive resin.
  • a treating amount of 5 wt. % or less, preferably 0.1-3 wt. %, may provide a sufficient dispersibility in the polymerizable monomer while not exerting a bad influence on the toner properties. It is also possible to use a mixture of lipophilic magnetic particles and hydrophilic magnetic particles.
  • the resultant polymerization toner is caused to have a low moisture resistance, and suffers from degradation in developing characteristic and anti-blocking property under high temperature-high humidity conditions.
  • a substantially water-insoluble polymerization initiator in order to produce a polymerization toner with excellent environmental characteristics, it is preferred to use a substantially water-insoluble polymerization initiator.
  • the substantially water-insoluble polymerization initiator preferably used in the present invention has a solubility of 1 g or less in 100 g of water, preferably 0.5 g or less in 100 g of water, particularly preferably 0.2 g or less in 100 g of water, respectively at room temperature.
  • the solubility is more than 1 g in 100 g of water
  • the decomposition product of the initiator remaining on the surfaces of the polymerization toner particles undesirably lowers the moisture resistance of the polymerization toner.
  • the polymerization initiator used in the present invention is soluble in the polymerizable monomer and has a property of being well dissolved in the monomer in an ordinarily used range of amount (1-10 wt. parts per 100 wt. parts of the monomer).
  • Examples of the polymerization initiator usable in the present invention may include: azo- or diazo-type polymerization initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, etc.; and peroxide-type polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide.
  • azo- or diazo-type polymerization initiators such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-
  • the polymerization initiator has a melting point equal to or lower than the polymerization temperature (generally, 50° C. or above). It is also preferred to use two or more polymerization initiators in mixture in order to control the molecular weight and molecular weight of the resultant polymer or in order to control the reaction time.
  • the amount of use of the polymerization initiator may be in the range of 0.1-20 wt. parts, preferably 1-10 wt. parts, per 100 wt. parts of the polymerizable monomer. Below 0.1 wt. part, it is difficult to distribute or provide the initiator evenly to individual monomer composition particles. Above 20 wt. parts is excessive to provide too low a molecular weight of the polymerization product and to increase the tendency that the polymerization occurs ununiformly.
  • the suspension polymerization is generally carried out at a polymerization temperature of 50° C. or higher, and the upper limit temperature may be set in consideration of the decomposition speed of the polymerization initiator. Too high a polymerization temperature is not desirable because the polymerization is decomposed too rapidly.
  • the temperature of the aqueous medium containing the particles is adjusted to a polymerization temperature (e.g. 55°-70° C.), thereby to cause suspension polymerization.
  • a polymerization temperature e.g. 55°-70° C.
  • a polar polymer (inclusive of copolymer) or cyclized rubber is added to a polymerizable monomer to be polymerized, a preferable polymerization toner having a pseudo-capsule structure can be obtained.
  • the polar polymer or cyclic rubber may preferably be added in an amount of 0.5-50 wt. parts, preferably 1-40 wt. parts, per 100 wt. parts of the polymerizable monomer. Below 0.5 wt. part, it is difficult to obtain a desired pseudo-capsule structure. Above 50 wt. parts, there arises an increased tendency that the characteristics of the polymerization toner are lowered because the amount of the polymerizable monomer becomes insufficient.
  • a polymerizable monomer composition containing the polar polymer or cyclized rubber thus added is suspended in an aqueous medium containing a dispersant dispersed therein having a chargeability to a polarity opposite to that of the polar polymer to be polymerized.
  • the cationic polymer (inclusive of copolymer), anionic polymer (inclusive of copolymer) or anionic cyclized rubber thus contained in the polymerizable monomer composition exerts an electrostatic force at the surface of toner-forming particles with the oppositely chargeable anionic or cationic dispersant dispersed in the aqueous medium, so that the dispersant covers the surface of the particles to prevent coalescence of the particles with each other and to stabilize the dispersion.
  • a sort of shell is formed to provide the particles with a pseudo-capsule structure.
  • Examples of the polar polymer (inclusive of copolymer and cyclized rubber) and the fine powdery dispersant or dispersion stabilizer having a chargeability usable in the present invention may be raised hereinbelow.
  • the polar polymer having a weight-average molecular weight of 5,000-500,000 as measured by GPC (gel permeation chromatography) is preferred because of good solubility in the polymerizable monomer and characteristic of providing a durable toner.
  • Cationic polymers polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl acrylate; copolymers of styrene and such a nitrogen-containing monomer; and a ternary copolymer of styrene; an unsaturated carboxylic acid ester and such a nitrogen-containing monomer.
  • Anionic polymers polymers or copolymers of anionic monomers inclusive of nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acid such as acrylic acid, unsaturated dibasic acids, and unsaturated dibasic acid anhydrides; and copolymers of styrene and such as anionic monomer. Cyclized rubber may also be used as an anionic polymer.
  • the fine powdery dispersion stabilizer may preferably be hardly water-soluble or substantially water-insoluble inorganic fine powder capable of stabilizing the dispersion of the monomer composition particles in an aqueous medium.
  • the amount of addition of the dispersant may preferably be 0.1-50 wt. %, particularly 1-20 wt. %, based on the water.
  • Anionic dispersant colloidal silica such as Aerosil #200, #300 (Nihon Aerosil K.K.), Nipsil E-220A (Nihon Silica); and Finesil T-32 (Tokuyama Soda K.K.)
  • Cationic dispersant aluminum oxide, magnesium hydroxide and hydrophilic positively chargeable silica fine powder such as aminoalkyl-modified colloidal silica obtained through treatment with a coupling agent.
  • a fine powdery dispersion stabilizer is used, but it is not necessary required to use a polar polymer or a fine powdery dispersant having chargeability opposite thereto in a liquid medium.
  • dispersion stabilizer examples include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginic acid salts, zein, casein, tricalcium phosphate, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide and thorium hydroxide.
  • a dispersion stabilizer include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginic acid salts, zein, casein, tricalcium phosphate, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide and thorium hydroxide.
  • One or more of these compounds may
  • the inorganic dispersion stabilizer In order to effect uniform dispersion of the inorganic dispersion stabilizer, it is possible to add a surfactant within an extent of not adversely affecting the process of the present invention.
  • the surfactant is used to promote the above mentioned dispersion stabilizer to show the prescribed function.
  • Such a surfactant include: sodium dodecylbenzenesulfonate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caproate, potassium stearate, calcium oleate, sodium 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, sodium 2,2,5,5-tetramethyl-triphenylmethane-4,4- diazo-bis- ⁇ -naphthol-disulfonate, and others.
  • a Broensted acid such as hydrochloric acid
  • a Broensted acid such as hydrochloric acid
  • the addition of a Broensted acid such as hydrochloric acid in the aqueous medium is effective in enhancing the effect of an anionic polymer (including copolymer) or cyclized rubber.
  • the polymerization toner according to the present invention is applicable to the known dry system methods for developing electrostatic images including the two-component developing methods such as the cascade method, the magnetic brush method, the microtoning method and the two-component AC bias developing method; the one-component developing methods using a magnetic toner such as the electroconductive one-component developing method, the insulating one-component developing method and the jumping developing method; the powder cloud method and the fur brush method; the nonmagnetic one-component developing method wherein the toner is carried on a toner-carrying member to be conveyed to a developing position and subjected to development thereat; and the electric field curtain method wherein the developer is conveyed by an electric field curtain to a developing position and subjected to development thereat.
  • the polymerization toner of the present invention is especially suitably applicable to the developing method, wherein a small particle size toner having a weight-average molecular weight of about 2-8 ⁇ with a sharp particle size as a requisite is used.
  • the above ingredients were mixed at 30° C. by means of an attritor to prepare a monomer composition.
  • the viscosity of the monomer composition at 60° C. was 300 cps.
  • the thus obtained monomer composition was charged in a 2 l-stainless steel vessel which already contained 5 g of amino-modified silica (obtained by treating 100 wt. parts of Aerosil 200 with 5 wt. parts of aminopropyltriethoxysilane), 600 g of distilled water and 20 g of 0.1N-hydrochloric acid, and the mixture was stirred at 60° C. for 10 minutes by means of a TK-homomixer (mfd.
  • the dispersion was subjected to cooling, dehydration, washing with water, dehydration and drying to obtain a polymerization toner.
  • the resultant toner showed a volume-average particle size of 4.9 ⁇ , and contained 5% by volume of fine particles with sizes below 2.52 ⁇ and 3% by volume of coarse particles with sizes over 8.0 ⁇ according the particle size measurement by means of a Coulter counter with an aperture of 100 ⁇ , thus showing a very narrow distribution.
  • An image-bearing member 8 has a selenium photosensitive member 19, which was rotated at a peripheral speed of 100 mm/sec, the maximum potential of an electrostatic image formed on the image bearing member was +750 V.
  • Opposite the image-bearing member 8 was disposed a sleeve 9 having an outer diameter of 20 mm and rotated at a peripheral speed of 100 mm/sec.
  • a magnetic flux of 1000 Gauss was exerted to the surface of the sleeve (developer-carrying member) 9 with a magnet roller 10 having poles of N 1 , N 2 , S 1 and S 2 .
  • a layer of the developer in a thickness of 200 ⁇ m was formed.
  • the sleeve 9 and the image bearing member 8 were disposed at gap of 300 ⁇ m.
  • the bias voltage applied to the sleeve comprised a DC component of +200 V, and an AC component of 3.0 KHz and 1400 Vpp.
  • the electrostatic image was satisfactorily developed.
  • the developed toner image was electrostatically transferred to plain paper, and fixed by passing through a hot roller fixing apparatus composed of a fixing roller surfaced with a silicone rubber layer and a pressure roller (nip width: 9 mm, paper moving speed of 300 mm/sec) under a pressure of 7 kg/cm 2 and at a fixing temperature of 150° C.
  • the resultant fixed image was free of fog and showed an image density (Dmax) of 1.44.
  • a toner T mixed with an external additive was quantitatively supplied to a lower chamber by means of an elastic member 14 and a supply roller 15, and mixed with a carrier to form a developer 11.
  • a DC bias was supplied from a DC bias supply 12, and an AC bias was supplied from an AC bias supply.
  • a developer regulating member 17 also functioned as an outer wall of the developing apparatus.
  • a polymerization toner was prepared in the same manner as in Example 1 except that the stirring by means of the TK homomixer was carried out for 60 minutes, and the injection pressure of the piston-type high-pressure homogenizer was changed to 400 kg/cm 2 .
  • the resultant toner showed a volume-average particle size of 2.1 ⁇ , and contained 3% by volume of fine particles with sizes below 1.26 ⁇ and 3% by volume of coarse particles with sizes over 5.04 ⁇ according the particle size measurement by means of a Coulter counter with an aperture of 50 ⁇ , thus showing a very narrow distribution.
  • a polymerization toner was prepared in the same manner as in Example 1 except that the amount of the amino-modified silica was charged to 1 g and the ejection pressure of the piston-type homogenizer was changed to 200 kg/cm 2 .
  • the resultant toner showed a volume-average particle size of 9.3 ⁇ , and contained 5% by volume of fine particles with sizes of below 5.04 ⁇ and 5% by volume of coarse particles with sizes of over 16 ⁇ .
  • a polymerization toner was prepared in the same manner as in Example 1 except that the amount of the amino-modified silica was charged to 10 g and the granulation through dispersion was conducted by using only the TK-homomixer for 60 minutes without using the high-pressure homogenizer.
  • the resultant toner showed a volume-average particle size of 11.0 ⁇ , and contained 15% by volume of fine particles with sizes of below 6.35 ⁇ and 15% by volume of coarse particles with sizes of over 16 ⁇ , thus showing a broader particle size distribution.
  • a developer was prepared and evaluated with respect to the electrophotographic characteristics in the same manner as in Example 1 except that the above toner was used.
  • the resultant image was accompanied with more fog than in Example 1 and showed a somewhat lower image density of 1.30.
  • a polymerization toner was prepared in the same manner as in Example 1 except that the amount of the amino-modified silica was charged to 25 g and the granulation through dispersion was conducted by using only the TK-homomixer for 60 minutes without using the high-pressure homogenizer.
  • the resultant toner showed a volume-average particle size of 5.1 ⁇ , and contained 20% by volume of fine particles with sizes of below 2.52 ⁇ and 15% by volume of coarse particles with sizes of over 8 ⁇ , thus showing a broader particle size distribution.
  • Example 1 was repeated except that the ejection pressure of the high-pressure homogenizer was charged to 8 kg/cm 2 , whereby the granulation efficiency was extremely low.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Polymerisation Methods In General (AREA)
US07/018,535 1986-03-03 1987-02-25 Process for producing toner for developing electrostatic images Expired - Lifetime US4702988A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP61045917A JPH0719076B2 (ja) 1986-03-03 1986-03-03 静電荷像現像用重合トナ−の製造方法
JP61-45917 1986-03-03

Publications (1)

Publication Number Publication Date
US4702988A true US4702988A (en) 1987-10-27

Family

ID=12732596

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/018,535 Expired - Lifetime US4702988A (en) 1986-03-03 1987-02-25 Process for producing toner for developing electrostatic images

Country Status (4)

Country Link
US (1) US4702988A (enrdf_load_stackoverflow)
JP (1) JPH0719076B2 (enrdf_load_stackoverflow)
DE (1) DE3706706A1 (enrdf_load_stackoverflow)
FR (1) FR2595097B1 (enrdf_load_stackoverflow)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4816366A (en) * 1987-02-13 1989-03-28 Canon Kabushiki Kaisha Process for producing toner through suspension polymerization
US4937167A (en) * 1989-02-21 1990-06-26 Xerox Corporation Process for controlling the electrical characteristics of toners
US4972200A (en) * 1988-03-24 1990-11-20 Canon Kabushiki Kaisha Image forming method and apparatus utilizing a voltage to change the adhesiveness of the ink to perform an ink cleaning step
US5043404A (en) * 1989-04-21 1991-08-27 Xerox Corporation Semisuspension polymerization processes
US5089295A (en) * 1990-11-05 1992-02-18 Xerox Corporation Suspension polymerization processes and toner compositions thereof
US5164282A (en) * 1989-04-17 1992-11-17 Xerox Corporation Processes for the preparation of toners
US5278018A (en) * 1991-05-22 1994-01-11 Xerox Corporation Magnetic toner compositions containing charge enhancing additive particles
US5474870A (en) * 1993-05-24 1995-12-12 Hodogaya Chemical Co., Ltd. Toner for developing electrostatic image and process for the preparation thereof
US5665506A (en) * 1995-01-31 1997-09-09 Hodogaya Chemical Co., Ltd. Toner for the development of electrostatic image and process for the preparation thereof
US5804349A (en) * 1996-10-02 1998-09-08 Xerox Corporation Acrylonitrile-modified toner compositions and processes
US6093770A (en) * 1998-02-02 2000-07-25 Xerox Corporation Polymers and processes thereof
US6406747B1 (en) 2000-11-28 2002-06-18 Xerox Corporation Methods of encapsulating cores using ink jets or fogs
US20080225210A1 (en) * 2007-03-08 2008-09-18 Fujifilm Corporation Optical Compensation Film, Polarizing Plate, and Liquid Crystal Display Device
US20080311501A1 (en) * 2007-06-18 2008-12-18 Sharp Kabushiki Kaisha Toner particles, method of manufacturing the same, two-component developer, developing device, and image forming apparatus

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4996127A (en) * 1987-01-29 1991-02-26 Nippon Carbide Kogyo Kabushiki Kaisha Toner for developing an electrostatically charged image
JP2736976B2 (ja) * 1988-07-21 1998-04-08 キヤノン株式会社 静電荷像現像用重合トナーの製造方法
JP2736975B2 (ja) * 1988-07-21 1998-04-08 キヤノン株式会社 静電荷像現像用重合トナーの製造方法
SE9101674L (sv) * 1991-05-31 1992-12-01 Berol Nobel Ab Dispersion

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4259465A (en) * 1978-05-01 1981-03-31 Gaf Corporation Bimodal coextendant suspension polymerization system

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7706989A (nl) * 1976-08-02 1978-02-06 Xerox Corp Werkwijze ter vorming van toners door polymerisa- tie.
JPS5918697B2 (ja) * 1980-08-27 1984-04-28 コニカ株式会社 静電荷像現像用トナ−
GB2091435A (en) * 1980-12-18 1982-07-28 Konishiroku Photo Ind Toner for developing electrostatic latent images
US4430251A (en) * 1981-09-29 1984-02-07 Hoffert Manufacturing Co., Inc. High energy emulsifier
US4592990A (en) * 1982-12-29 1986-06-03 Canon Kabushiki Kaisha Process for producing toner

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4259465A (en) * 1978-05-01 1981-03-31 Gaf Corporation Bimodal coextendant suspension polymerization system

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4816366A (en) * 1987-02-13 1989-03-28 Canon Kabushiki Kaisha Process for producing toner through suspension polymerization
US4972200A (en) * 1988-03-24 1990-11-20 Canon Kabushiki Kaisha Image forming method and apparatus utilizing a voltage to change the adhesiveness of the ink to perform an ink cleaning step
US4937167A (en) * 1989-02-21 1990-06-26 Xerox Corporation Process for controlling the electrical characteristics of toners
US5164282A (en) * 1989-04-17 1992-11-17 Xerox Corporation Processes for the preparation of toners
US5043404A (en) * 1989-04-21 1991-08-27 Xerox Corporation Semisuspension polymerization processes
US5089295A (en) * 1990-11-05 1992-02-18 Xerox Corporation Suspension polymerization processes and toner compositions thereof
US5278018A (en) * 1991-05-22 1994-01-11 Xerox Corporation Magnetic toner compositions containing charge enhancing additive particles
US5474870A (en) * 1993-05-24 1995-12-12 Hodogaya Chemical Co., Ltd. Toner for developing electrostatic image and process for the preparation thereof
US5665506A (en) * 1995-01-31 1997-09-09 Hodogaya Chemical Co., Ltd. Toner for the development of electrostatic image and process for the preparation thereof
US5804349A (en) * 1996-10-02 1998-09-08 Xerox Corporation Acrylonitrile-modified toner compositions and processes
US6093770A (en) * 1998-02-02 2000-07-25 Xerox Corporation Polymers and processes thereof
US6406747B1 (en) 2000-11-28 2002-06-18 Xerox Corporation Methods of encapsulating cores using ink jets or fogs
US20080225210A1 (en) * 2007-03-08 2008-09-18 Fujifilm Corporation Optical Compensation Film, Polarizing Plate, and Liquid Crystal Display Device
US20080311501A1 (en) * 2007-06-18 2008-12-18 Sharp Kabushiki Kaisha Toner particles, method of manufacturing the same, two-component developer, developing device, and image forming apparatus

Also Published As

Publication number Publication date
FR2595097B1 (fr) 1992-07-03
JPH0719076B2 (ja) 1995-03-06
JPS62203167A (ja) 1987-09-07
DE3706706A1 (de) 1987-10-08
DE3706706C2 (enrdf_load_stackoverflow) 1991-06-13
FR2595097A1 (fr) 1987-09-04

Similar Documents

Publication Publication Date Title
US4816366A (en) Process for producing toner through suspension polymerization
US4702988A (en) Process for producing toner for developing electrostatic images
US4626489A (en) Process for producing toner for development of electrostatic images by stepwise suspension polymerization
US4845007A (en) Process for producing toner through suspension polymerization
US4804610A (en) Process for producing toner by suspension polymerization method
US4912010A (en) Process for producing toner
EP0834779B1 (en) Process for producing toner for developing electrostatically charged images
US4789617A (en) Production of toner through polymerization
US5952144A (en) Production process of toner for development of electrostatic latent image
JP2736975B2 (ja) 静電荷像現像用重合トナーの製造方法
JPS63195659A (ja) 静電荷像現像用トナ−の製造方法
JP2505773B2 (ja) 画像形成方法及び装置
JPH0782248B2 (ja) 重合トナーの製造方法
JPS63198075A (ja) 重合トナ−の製造方法
JPS62266559A (ja) トナ−の製造方法
JPS63195661A (ja) 静電荷像現像用トナ−の製造方法
JPS63165869A (ja) 静電荷像現像用トナ−の製造方法
JPS63113561A (ja) 重合トナ−の製造方法
JPH0713762B2 (ja) トナ−の製造方法
JP2736976B2 (ja) 静電荷像現像用重合トナーの製造方法
JPH1020547A (ja) 重合トナー
JPS63195660A (ja) 静電荷像現像用トナ−の製造方法
JPS62299862A (ja) 静電荷像現像用トナ−の製造方法
JPS63247760A (ja) 重合トナ−の製造方法
JPS63243962A (ja) 静電荷像現像剤

Legal Events

Date Code Title Description
AS Assignment

Owner name: CANON KABUSHIKI KAISHA, 3-30-2 SHIMOMARUKO, OHTA-K

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:FUKUMOTO, HIROSHI;OHNISHI, TOSHIKAZU;ARAHARA, KOHZOH;REEL/FRAME:004673/0422

Effective date: 19870218

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FPAY Fee payment

Year of fee payment: 4

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12